marshall



Patented July 14, 1868.

c. K. MARSHALL.

Heating Stove.

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Letters Pqtent No. 79,3 14, dated July 14, 1868; (interlaced Jttlytl, 186,8.

IMPROVEMENT IN HOT-AIR PLUES. IN STOVES.

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-ro ALL WHOM IT MAY concerns:

Be it known that I, O. K. -MARSHALL, ot New Orl'eans, parish of Orleans, and State of Louisiana, have invented certain new and useful'lmprovements in Stoves; and I do hereby declare that the following is afull, .clear, and exact description of the some, reference beingbad to the annexed drawings, and to the letters of reference marked thereon, and makingpart of thisspecifica-tion, and in which- Figure 1 is a side View of a stove, showing the openings through which pass the elbow of the interior pipe.

Figure 2 is a sectional viewfsbowing the internal arrangement of pipes.

Figure 3 is a plan view.

Figure 4 is a detached view of the supplemental grate.

Figure 5 are sectional views of the interior pipe, showing its tapering flue:

It it a well-known and admitted fact that, in all stoves now in general use, but a small portion of the heat caused by the combustion of the fuelis ever received into the room or apartment that it is desired to heat. Various reasons might be advanced by which, on philosophical principles, the cause might be assigned why this is so. Perhaps the most prominent cause is found in this fact: The opening for the pipe, which connects the stove with the chimney, is invariably placed in the upper portion of the stove, and, as heated air naturally ascends, the heat caused by the combustion ot' the fuel is necessarily thrown into'the upper portion of the cylinder or drum of the stove, and, coming in contact with the opening for the pipe, a large portion of the warm air is borne through to the pipe, and escapes by the chimney-fiue, while but a small portion of the heat is radiated fromthe stove to aid in warming the apartment. Various attempts have been made to remedy this evil, but they all, more or less, 'interfere with the freedom of the draught, which it is absolutelyneeessary should be left open and unobstructed, otherwise it is impossible that the fuel can be properly ignited, or kept burning with the required freedom. v I

The object of my invention consists in a simple and practical method whereby, by means of one or more pipes properly introduced and'arranged in an ordinary stove, the heating properties of the same are-morc than doubled. i g

The nature of myinvention consists in constructing apipe of fire-clay, soapstone, or other equivalent material, said pipe being provided with two short elbows, extending at right angles therefrom, and which are intended to project through suitable openings arranged in the stove, one immediately above the grate, and the other in the upper portion of the stove. The lower elbow, which forms the base of the pipe, is intended to rest on the grate. Through this elbow, a constant current of fresh air is introduced't'rom the apartment, and being. heatcdin its transit through the main pipe, which is arranged sufliciently far from the side of the stove to allow ,.ofits being completely embedded in the burning fuel, is discharged by the upper elbow into the room.

In hall and other stoves of that class, which are provided with drums, the upper elbow, and consequently the upper opening in the stove, may be; dispensed with, and the pipe be continued through a suitable aperture arranged in the top of the stove, causing the current of air to be conveyed immediately into the drum, from which' it may be discharged, by means of appropriate registers, or other equivalent devices, at pleasure, or asthe temperature of the room may require.

Another most important feature of my invention consists in constructing this interior pipe-with a tapering flue, that is, one which is oi" much greater diameter or capacity at its base than at the point where the air is discharged. The great advantage of this tapering'fiue is this: the volume of air which is introduced is not permitted to rush through the pipe, as would be the case were the flue straight, and its sides perfectly parallel throughout their entire length. The volume is retarded sufiiciently in its passage through the fiu'e to insure the same being properly heated before being throwp into the apartment or discharged into the room. 7

My invention also consists in attaching, by means of suitable guide and bearing-rods, or equivalent devices, immediately below an ordinary grate, a supplemental grate. The bars of the lower or supplemental grate, instead of being round, are flat, and-much deepcrthan are those of the ordinary grate now in general use. i

The bars of the lower grate are so arranged that, when the same is worked by a lever or other suitable device, the bars of the lower enter between the'bars ofthc upper grate, and thus, when the stove is raked, the

entire mass of coal is agitated at one and the same time, and all the violent shock, which is so destructive to the inner tiling of the stove, when raked by any of the means new in general usc is entirely avoided.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construe lien and operation.

A is an ordinary stove, andrests on a suitable base, B. G is a flanged opening, to which the stove-pipe is attached. "D is aninterior pipe, and is made of fire-clay, soapstone, or other like material. at and d are two elbows, extending at right angles from the pipe D,an d pass out at suitable openings a b in the side of the stove.

The base of the elbow d is flattened, and rests on the grate. Through this elbow cl, ,a constant current of fresh air .is introduced to the pipe D, which being completely encircled by the burning fuel, or in ages-stove, in immediate contact withthe blaze, is thoroughly heated in its passage, and discharged into the room by means of the elbow d. When the stove has a drum or upper chamber, the elbow 03 may be dispensed with, and the pipe D continued through the. top of the stove, causing the current of heated air to be poured into the drum or chainber, from which it can be conveyed tothe'apartment through the agency of the registers or other equivalent devices.

This elbow (2' may be connected with the'stove-pipe C by a ,short pipe, c, provided with a damper. The object of this pipe is to allow of the course of the heated air being changed, when the room becomes uneomfortably warm; instead of being thrown into the same, it can'be' caused to passthrough the pipe e to'the stove-pipe C, and thence escape through the chimney-flue.

The discharge-elbow cl may have attached to it an outer pipe, 0, as shown in fig. 1, by means of which the heated air can be conveyed to a position near the door, or to any other part of the apartment desired. 1

E is thegrate, and is constructed in the usual manner. F is a-supplemental grate, and has its bearing in suitable guide-rods ff, which are firmly secured to the bottom of the stove A. f is a lever, attached to the supplemental grate F, and by which it is operated. G is an ash-pan, having a recess, g, and which serves as a fulcrum forthe lever f to work on. v

v The'bars of the supplemental grate F are fiat, and much deeper than are the bars of the ordinary grate.

These bars are so arranged that they enter and work between the barsof the upper grate E.

Byworking the leverf with the foot or hand, the entire mass oi' fuel can readily and uniformly be raked at one and the same time.

It will be observed that thcjpipe D is shown in fi 2 with a straight -flne, the diameter of the upper and lower sections being the same; while in fig. 5 the pipe D is shown with a tapering flue, the diameter being much greater at its contact with the elbow 01, through which the fresh air enters, than it is at its point of contact with the elbow d, through which the heated air is discharged.

' In some stoves, the straight the will do, for instance, where the height of the stove is very great, but, in

v a majority of cases, practical experience demonstrates that the air enters through the elbow 01 with such force that, when the line is straight, it rushes through the pipe I) and is discharged by the elbow l with such rapidity that time has not been allowed the air in its passage to become thoroughly heated. This defect is entirely remedied by constructing the pipe D with a tapering flue.

The volume of air that is introduced by the'elbow d doesnot pour in one continuous stream, but, in consequence of the fact that the capacityof the flue is much greater in its lower than inits upper section, the passage of the air is of necessity retarded longer than would bethe case where the flue is straight and its sides parallel.

This detention is suilieiently long to insure that the air, will be properly heated when discharged at the mouth of the elbow d. v

Having thus fully described my invention, what I claim therein as new, and desire to secure by Letters Patent of the United States, is-

I 1. Constructing the pipe D of fire-clay, soapstone, or other like material, with a tapering flue, substantially as described, and for the purpose specified.

2. Constructing the stove A with openingsab, in combination with the pipe, having. elbows d and at, when the same are constructed of fire-clay, soapstone, orot-her like materiahahd arranged so asto operate substantially as described, and'for the purpose specified. i

In testimony whereot',l have signed my name to this specification in the presence oftwo subscribing witnesses.

e. K. MARSHALL.

Witnesses:

JOHN D. BLOOB, JonN'S. HOLLINGSHEAD. 

